Spices steam distillation

Essential Oils. Volatile oils from plants are referred to as essential oils. The oils can be obtained through steam distillation, solvent extraction, or separation of the oils from pressed fmit. They consist of oxygenated compounds, terpenes, and sesquiterpenes. The primary flavor components of essential oils are oxygenated compounds. Terpenes contain some flavors but are often removed from the essential oil because they are easily oxidized (causiag off-flavors or odors) and are iasoluble. Essential oils are prepared from fmits, herbs, roots, and spices. 

Pepper oil and pepper oleoresin are obtained from the black pepper Piper nigrum L. (Piperaceae). Pepper oil is produced by steam distillation of whole or crushed fruits. The oil is an almost colorless to bluish-green liquid with a characteristic odor, reminiscent of pepper, but without the pungency of the spice. 

Another important group is the essential oils which are manufactured mainly from herbs and spices mostly by steam distillation. The advantage of steam distillation is the fact that a clean and powerful oil can be isolated after the distillation step without waxes and other non-volatile compounds but with an odour... 

The antioxidant activity of rosemary and sage (leaves and extracts) were most effectively investigated [96,97], Traditional extracts of spices and herbs are obtained by steam distillation (essential oil) or by extracting the botanical with solvents such as alcohol, hexane, or acetone, and removing the solvents by evaporation. The SFE process for production of the inherent natural antioxidants is now the most gentle and effective method [70],... 

The odour of pepper oil is described as fresh, dry-woody, warm-spicy and similar to that of the black peppercorn (Purseglove et al., 1981). The flavour is rather dry-wood and lacks the pungency of the spice since the alkaloids are not extracted by steam distillation. Very few studies are reported in the literature on correlation of oil composition to odour characteristics. Hasselstrom et al. (1957) attribute the characteristic odour of pepper oil to the small amounts of oxygenated constituents present. Lewis etal. (1969) consider that a number of monoterpenes present in the oil are necessary for strong... 

Borges, P., Fernandez, N. and Roncal, E. (2003) Isolation and characterization of essential oils of spice plants using steam distillation. Alimentaria 40(340), 125-127. 

Cumin oil is usually obtained by steam distillation of the milled spice hydrodiffusion gives a higher yield and, more recently, supercritical gaseous extraction is claimed to give oil closer to the aroma and taste of the spice (Eikani et al., 1999). The yields of cumin seed oil with steam distillation are 2.3-3.6%, with liquid carbon dioxide it is 4.5% and with ethanol it is 12%. The major components are cuminaldehyde, cuminyl alcohol, p-mentha and 1.3-dien-7-al, the minimum perceptible levels being at 0.2 ppm. Naik et al. (1989) reported that liquid C02 extraction was quicker than steam distillation for the quantitative extraction of cumin oil without loss of active flavour components, at 58 bar and 20°C. 

This experiment is intended to illustrate the complementary nature of analytical LC with steam distillation by measuring the composition of a steam-distilled extract of a spice. 

Clove oil may be obtained from cloves by steam distillation. A number of other spices may be used for extracting other oils (9,10) whose structures are shown in Table 16-1. The essential oils are rich in one main compound and since all components are UV absorbing, the fixed wavelength detector at 254 nm is adequate for detection. Liquid chromatography is a rapid analytical tool in analyzing the essential oils. 

The examples discussed above clearly demonstrate that C02-extraction is a more gentle procedure than steam distillation. The smaller processing stress widely avoids the formation of artefacts. Therefore C02-extracts often have a better efficacy or a richer aroma profile reflecting the complete flavour or fragrance spectrum of the herbal raw material. This is also confirmed in the literature where professional fla-vourists have compared the aroma profiles of C02-extracts, essential oils and oleores-ins for a range of different spices [7]. Moreover C02-extraction is carried out under precisely standardised and controlled conditions which allow reproducible results. Since C02-extracts have their own character different from the usual distillates, they are new and powerful means for flavourists and food technologists to modify, improve or boost existing products or to create new premium flavour qualities. 

There are two marketed ingredients which are not available as kosher natural cognac oil and wine fusel oil. All fruits and vegetables (except from Israel) are kosher, all steam distilled essential oils, spices, inorganic compounds, most FD C colors, petrochemicals, and all turpentine derivatives are kosher Ingredients that are, or can be derived from, grape are very sensitive for kosher. This impacts juices, vinegars, and some alcohols. 

The other class of lipid molecnles, based on a branched five-carbon stmc-ture called isoprene, was first identified via steam distillation of plant materials. The extracts are called essential oils. They are often fragrant, and are used as medicines, spices, and perfumes. A wide variety of structures is obtained by fusing isoprene monomer units, leading to a very diverse set of compounds, including terpenes, such as j8-carotene, pinene (turpentine), and carvone (oil of spearmint) and steroids, such as testosterone, cholesterol, and estrogen. 

Many plants, used as spices or flavor ingredients, are preserved by drying and are ideal matrices for SFE. Once ground to a powder, they have a large surface area and are highly permeable, leading to rapid and efficient extractions. Interest in SFE of plants has principally been for the isolation of essential oils, but recently SFE has also been used to obtain pharmaceutically active compounds. The extraction of the sesquiterpene lactone parthenolide (Fig. 5) from feverfew plants has been described by Smith (30) and Smith and Burford (31). SFE was compared with steam distillation and solvent extraction. While SFE extracted the less-volatile lactones and parthenolide, the steam distillation extracted the volatile terpenes. SFE resulted in incomplete extraction compared... 

The structure elucidation of salicylic acid we owe to Hermann Kolbe (1818-1884) and Victor Meyer (1848-1897). Also its industrial synthesis, from phenol and carbon dioxide, can be traced back to Kolbe, who developed this process in 1874. Previously, salicylic acid was produced by hydrolysis of its methyl ester, which in turn was obtained from wintergreen oU, a product of the steam distillation ofthe leaves ofthe American wintergreen oiteaheiry (Gaultheria procutn-bens) and the spice birch (Betula lento). 

Essential oils are volatile compounds responsible for the aromas commonly associated with many plants (see essay "Terpenes and Phenylpropanoids")- The chief constituent of the essential oil from cloves is aromatic and volatile with steam. In this experiment, you will isolate the main component derived from this spice by steam distillation. Steam distillation provides a means of isolating natural products, such as essential oils, without the risk of decomposing them thermally. Identification and characterization of this essential oil will be accomplished by infrared spectroscopy. 

In Experiment 54A, you will steam-distill the essential oil from a spice. You will choose, or the instructor will assign you, a spice from the following list caraway, cinnamon, cloves, cumin, fennel, or star anise. Each spice produces a relatively pure essential oil. The structures for the major essential oil components of the spices are shown here. Your spice will yield one of these compounds. You are to determine which structure represents the essential oil that was distilled from your spice. 

In Experiment 54A, we have assumed that each of the spices provides one major product in the steam distillation. HPLC analysis lets you test whether or not this assumption is correct. You should also be able to determine the percentage of the major essential oil component in the distillate. 

Finally, a variety of additional spices and herbs can be investigated by a combination of steam distillation and GC-MS analysis (Experiment 54C). This experiment is intended to be a mini-research project. Your instructor will assign you a particular spice or herb to analyze, or you will choose your own plant material. In this project, you will not have advance information about the components of the plant material that you investigate. 

If ground spices are used, you may want to have the students insert a Claisen head between the round-bottom flask and the distillation head to allow extra volume in case the mixture foams. Problems with foaming can be greatly ameliorated by applying an aspirator vacuum to the spice-water mixture before the steam distillation is begun. 

Obtain a sample of essential oil by steam distillation of the spice, according to the method shown in Experiment 54A. 

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